linear_congruential_engine Class

  • Artikel

Generates a random sequence by the linear congruential algorithm.

template<class UIntType, UIntType A, UIntType C, UIntType M>
class linear_congruential_engine;

Parameters

  • UIntType
    The unsigned integer result type. For possible types, see <random>.

  • A
    Multiplier. Precondition: See Remarks section.

  • C
    Increment. Precondition: See Remarks section.

  • M
    Modulus. Precondition: See remarks.

Members

linear_congruential_engine::linear_congruential_engine

linear_congruential_engine::min

linear_congruential_engine::discard

linear_congruential_engine::operator()

linear_congruential_engine::max

linear_congruential_engine::seed

default_seed is a member constant, defined as 1u, used as the default parameter value for linear_congruential_engine::seed and the single value constructor.

For more information about engine members, see <random>.

Remarks

The linear_congruential_engine template class is the simplest generator engine, but not the fastest or highest quality. An improvement over this engine is the substract_with_carry_engine. Neither of these engines is as fast or with as high quality results as the mersenne_twister_engine.

This engine produces values of a user-specified unsigned integral type using the recurrence relation (period) x(i) = (A * x(i-1) + C) mod M.

If M is zero, the value used for this modulus operation is numeric_limits<result_type>::max() + 1. The engine's state is the last value returned, or the seed value if no call has been made to operator().

If M is not zero, the values of the template arguments A and C must be less than M.

Although you can construct a generator from this engine directly, you can also use one of the predefined typedefs in the following table.

Name

Description

minstd_rand0

1988 minimal standard engine (Lewis, Goodman, and Miller, 1969).

typedef linear_congruential_engine<unsigned int, 16807, 0, 2147483647> minstd_rand0;

minstd_rand

Updated minimal standard engine minstd_rand0 (Park, Miller, and Stockmeyer, 1993).

typedef linear_congruential_engine<unsigned int, 48271, 0, 2147483647> minstd_rand;

For detailed information about the linear congruential engine algorithm, see the Wikipedia article Linear congruential generator.

Requirements

Header: <random>

Namespace: std

See Also

Reference

<random>